Technical Field
The present invention relates to a technology of creating information regarding external vibration using a vibration-powered generator that generates electricity from external vibration using an electret.
Related Art
Lately, demands on using electricity obtained by detecting external vibration generated in a constructional structure such as a bridge or a road in maintenance of the constructional structure remarkably increase. For example, a vibration displacement of external vibration applied to a constructional structure significantly affects a strength change of the constructional structure, and demands on detection thereof are relatively significant. In this regard, in the related art, the vibration displacement was detected using a laser displacement sensor or electromagnetic energy (for example, refer to Patent Literature 1). In the technique discussed in Patent Literature 1, information regarding a displacement of the external vibration is detected by controlling a response of a vibrator that responds to external vibration using a coil and a service power supply.
Meanwhile, a vibration-powered generator using an electret, capable of generating electricity from external vibration, has been developed (for example, refer to Patent Literature 1). In the technique discussed in Non-patent Literature 1, electric power of 6 μW is generated from external vibration having an amplitude of 1 mm and a frequency of 10 Hz using an electret. However, this technique fails to disclose a configuration of appropriately detecting information regarding a velocity or a displacement of external vibration using a vibration-powered generator that has an electret and performs vibration-induced power generation from external vibration.